1. Field of the Invention
The invention relates to shoes having retractable spikes and, more particularly, to shoes having spikes that are easily retractable for facilitating swinging a golf club and a method of using the shoes.
2. Description of the Related Art
In executing a golf swing correctly, it is important that the golfer end up facing the target. Unfortunately, most golfers cannot successfully make this movement when they are wearing a standard pair of spiked golf shoes because the spikes of the shoes root their feet to the ground. Restraining movement of the golfer's front foot makes it difficult for the average golfer to make the proper turn during the golf swing so that his body is properly facing the target at the end of the swing.
As a result of not being able to make the proper turn through the ball with the body facing the target at the end of the golf swing, the hips and shoulders of the golfer "pile up" and the golfer is not able to deliver the power of the big muscles of the back and shoulders in the desired manner. In addition, when the hips and shoulders "pile up," tremendous strain is placed on the ankles, knees, front hip and back of the golfer. This results in many injuries of varying degree each year.
During the golf swing there should also be a translational component of motion during the downswing, and conventionally spiked golf shoes which have the purpose of firmly rooting the golfer to the ground do not permit this translational component of motion. As a result, the average golfer is forced to make an unbalanced follow-through with improper weight transfer to the forward foot.
Various modifications to conventional spiked golf shoes have been attempted to enable a golfer to make the proper movements during the golf swing without injury. For example, U.S. Pat. Nos. 1,304,616 and 5,243,776 describe golf shoe constructions which are provided with pivoted spike-supporting plates. The golfer wears the shoes on each foot so that both feet are permitted to rotate during the golf swing.
Unfortunately, if both feet of the golfer are permitted to rotate during the golf swing, a proper swing does not result. This is because it is important for the golfer's rearward foot to remain firmly positioned during the backswing so that resistance and forces are built-up by the coiling action of the golfer's torso and arms around the rear leg. This storing of energy on the backswing is not facilitated by use of the shoes described in the patents noted above because the entire body and legs of the golfer are able to rotate. As a result, the necessary tension and coiling potential would not be created between the golfer's torso and arms and his rearward leg during the backswing. Also, the shoes disclosed in the '616 and '776 do not permit the golfer's front foot to have a translational component of motion.
Additionally, the use of retractable spikes in various shoes is known. For example, U.S. Pat. No. 4,375,729 describes a shoe having retractable spikes for use on snow or ice. A cam moves longitudinally within a hollow sole to move the spikes into a projecting position and to withdraw the spikes into a retracted position. A control for moving the cam is accessible through a flexible wall at the rear of the heel of the shoe. Therefore, the user must bend down, lift the shoe and balance on one foot, or remove the shoe, to change the status of the spikes.
U.S. Pat. No. 4,825,562 discloses a shoe for use in snow or ice having retractable spikes that are manipulated by a rotary dial. The dial is accessed from inside the shoe, and thus the shoe requires either a highly flexible insole so that the handle of the dial may be grasped through the insole, or requires that the insole be partially removed. In either configuration, the shoe must be removed to access the dial.
U.S. Pat. No. 5,526,589 discloses a shoe having retractable spikes and an inflatable bladder which causes the spikes to retract when inflated. A pump and an exhaust air valve are disposed within the upper of the shoe for inflating and deflating the bladder thus requiring that the user lift the shoe and balance on one foot, remove the shoe, or bend over the operate the pump manually. Also, the pump must be operated several times to retract the spikes.
U.S. Pat. No. 5,497,565 also discloses a shoe having retractable spikes. The spikes are coupled to a complex motion translation device to change from a retracted state to a projecting state in response to manual rotation of a knob on the back of the heel of the shoe; thus also requiring that the user bend down, balance on one foot, or remove the shoe, to change the status of the spikes. Also, the knob must be rotated through a large angular displacement to move the spikes through a full stroke.
It is, therefore, an object of the present invention to readily enable the golfer to complete the follow-through during the golf swing so that the golfer's body is properly facing toward the target at the end of the golf swing.
Another object of the invention is to permit the rearward foot of the golfer to remain firmly rooted and fixed in position with respect to the ground during the backswing but permit the forward foot of the golfer to slidably rotate with respect to the ground during the follow-through of the golf swing.
A further object of the invention is to enable the golfer's forward foot to have a translational component of motion during the golf swing.
Still another object is to simplify maintenance in the manufacture of a pair of shoes for use by golfers.
A still further object of the invention is to reduce golf related injuries.
Yet another object of the invention is to enable a golfer to deliver the power of the big muscles of the back and shoulders in the most effective manner during the golf swing.
Still another object of the invention is to allow the golfer's body parts to turn freely during the golf swing.
Another object of the invention is to permit a golfer to selectively retract or extend spikes of at least one golf shoe with minimal effort.
It is also an object of the invention to provide retractable spikes on the sole over a large area, while requiring only one operating member to control all spikes.
A still further object of the invention is to enable projection and retraction of spikes without requiring the wearer to bend over to operate controls by hand or remove the shoe.
Still another object of the invention is to provide ground engaging surfaces of the shoe which are appropriate for various ground conditions.
The above objects are attained by a pair of golf shoes in which at least one of the shoes has retractable spikes. In one aspect of the invention the shoe has a chamber formed in the sole. A rotary cam member is disposed in the chamber and when rotated to a first position, forces spikes to project through openings in the sole. When the cam member is rotated to a second position, the spikes retract into the sole. A control lever for rotating the cam projects laterally to the exterior of the sole. The control lever can be operated and thus the spikes can be retracted or projected, by moving the shoe along the ground or other surface in a predetermined manner.
This construction permits appropriate body movement, thereby improving accuracy, enabling full muscular effort to be achieved, and mitigating strain imposed upon the body. Also, a significant portion of sole area may be devoted to bearing weight. Further, the shoe need not be removed to project and retract spikes. The lever may be moved by sliding the side of the shoe against the ground or other surface.
In another aspect of the invention replaceable lower sole members are provided on the shoes. The lower sole members have surface characteristics appropriate for different ground conditions, such as dry, wet, or normal. The appropriate lower sole member is selected based on conditions of a playing surface.
Another aspect of the invention is a method of swinging a golf club while wearing at least one shoe with retractable spikes comprising the steps of retracting the spikes of a shoe worn on the front foot, swinging the golf club, and subsequently causing the spikes to project again.
Another aspect of the invention is a method of retracting the spikes of a shoe comprising, rotating the shoe about the wearer's ankle, engaging an operating member of the shoe with the ground, and sliding the shoe relative to the ground to move the operating member and cause a retraction device in the shoe to retract the spikes.
Another aspect of the invention is a shoe package including a container, a first shoe disposed in the container and having a plurality of spikes, and a second shoe disposed in the container and having a smooth spikeless sole.